Multiple nearest-neighbor exchange model for the frustrated magnetic molecules Mo72Fe30 and Mo72Cr30

Our measurements of the differential susceptibility dM/dH of the frustrated magnetic molecules Mo72Fe30 and Mo72Cr30 reveal a pronounced dependence on magnetic field (H) and temperature (T) in the low H - low T regime, contrary to the predictions of existing models. Excellent agreement with experiment is achieved upon formulating a nearest-neighbor classical Heisenberg model where the 60 nearest-neighbor exchange interactions in each molecule, rather than being identical as has been assumed heretofore, are described by a two-parameter probability distribution of values of the exchange constant. We suggest that the probability distribution provides a convenient phenomenological platform for summarizing the combined effects of multiple microscopic mechanisms that disrupt the idealized picture of a Heisenberg model based on a single value of the nearest-neighbor exchange constant.Comment: 8 pages, 5 figure

Insights into the pathogenesis of nicotine addiction. Could a salivary biosensor be useful in Nicotine Replacement Therapy (NRT)?

Nicotine has gained the attention of the medical community due to its insidious addictive mechanisms which lead to chronic consumption. The multitude of compounds derived from tobacco smoke have local and systemic negative impacts, resulting in a large number of smoking-related pathologies. The present review offers insights into nicotine addiction physiopathology, as well as social and medical implications, with emphasis on its correlation with Advanced Glycation End Products (AGEs). Therapeutic strategies and new approaches to nicotine assessment and cessation treatment are discussed, noting that such strategies could take into account the possibility of slow and gradual nicotine release from a device attached to a prosthetic piece, based on salivary nicotine-concentration feedback. This approach could offer real-time and home-based self-therapy monitoring by the physician and the patient for follow-up and improve long-term cessation treatment success- Graphical abstract

Calculating the energy spectra of magnetic molecules: application of real- and spin-space symmetries

The determination of the energy spectra of small spin systems as for instance given by magnetic molecules is a demanding numerical problem. In this work we review numerical approaches to diagonalize the Heisenberg Hamiltonian that employ symmetries; in particular we focus on the spin-rotational symmetry SU(2) in combination with point-group symmetries. With these methods one is able to block-diagonalize the Hamiltonian and thus to treat spin systems of unprecedented size. In addition it provides a spectroscopic labeling by irreducible representations that is helpful when interpreting transitions induced by Electron Paramagnetic Resonance (EPR), Nuclear Magnetic Resonance (NMR) or Inelastic Neutron Scattering (INS). It is our aim to provide the reader with detailed knowledge on how to set up such a diagonalization scheme.Comment: 29 pages, many figure

Development of microspheres for biomedical applications: a review

An overview of microspheres manufactured for use in biomedical applications based on recent literature is presented in this review. Different types of glasses (i.e. silicate, borate, and phosphates), ceramics and polymer-based microspheres (both natural and synthetic) in the form of porous , non-porous and hollow structures that are either already in use or are currently being investigated within the biomedical area are discussed. The advantages of using microspheres in applications such as drug delivery, bone tissue engineering and regeneration, absorption and desorption of substances, kinetic release of the loaded drug components are also presented. This review also reports on the preparation and characterisation methodologies used for the manufacture of these microspheres. Finally, a brief summary of the existing challenges associated with processing these microspheres which requires further research and development are presented

Lipase-catalysed esterification in a reactive natural deep eutectic solvent leads to lauroylcholine chloride rather than glucose ester

Enzymatic esterification of glucose with lauric acid catalyzed by lipase B from Candida antarctica immobilized on acrylic resin (LAR) was investigated in hydrophilic reactive natural deep eutectic solvents (R-NADESs), composed of choline chloride (ChCl) as the hydrogen bond acceptor (HBA) and glucose (Glc) and water as hydrogen bond donors (HBDs) in different molar ratios. Surprisingly, no glucose esters were obtained, the only esterification product being lauroylcholine chloride, obtained in the ChCl : Glc : H2O (2 : 1 : 1) ternary R-NADES. Molecular dynamic simulations clearly explained this unexpected selectivity, showing that the lipase-catalyzed synthesis of glucose lauryl esters is hindered by the manifold and strong interactions in the H-bond network and the formation of voluminous adducts of glucose with the chloride ion, which cannot access the alcohol catalytic subsite. The free choline chloride, not involved in the H-bond network of the ChCl : Glc : H2O (2 : 1 : 1) R-NADES, did enter the CalB catalytic pocket and was converted to the corresponding lauroylcholine ester

Insights into the pathogenesis of nicotine addiction. Could a salivary biosensor be useful in Nicotine Replacement Therapy (NRT)?

Nicotine has gained the attention of the medical community due to its insidious addictive mechanisms which lead to chronic consumption. The multitude of compounds derived from tobacco smoke have local and systemic negative impacts, resulting in a large number of smoking-related pathologies. The present review offers insights into nicotine addiction physiopathology, as well as social and medical implications, with emphasis on its correlation with Advanced Glycation End Products (AGEs). Therapeutic strategies and new approaches to nicotine assessment and cessation treatment are discussed, noting that such strategies could take into account the possibility of slow and gradual nicotine release from a device attached to a prosthetic piece, based on salivary nicotine-concentration feedback. This approach could offer real-time and home-based self-therapy monitoring by the physician and the patient for follow-up and improve long-term cessation treatment success- Graphical abstract

Impact of smoking exposure on disease progression in high risk and very high-risk nonmuscle invasive bladder cancer patients undergoing BCG therapy

Introduction: The nonmuscle invasive bladder cancer treated with BCG instillations in patients who smoke could potentially lead to poorer oncological results in the light of the new EAU risk groups classification for NMIBC that did not include BCG treated patients or smoking status. Patient and Methods: Outcomes from 1313 patients with nonmuscle invasive bladder cancer treated with TURBT, re-TURBT and BCG instillations at 13 academic hospital centers, since 2002, has been included in this retrospective study. The study variables, including cumulative smoking exposure have been analyzed. A multivariable Cox proportional hazard model was used to assess associations between smoking variables and disease progression and repeated in the EAU high risk and very high-risk group. The statistical significance threshold was set at 0.05, and the statistical analysis was performed using Stata/SE version 17 (StataCorp, College Station, TX, USA). Results: Cox regression analysis revealed in 1313 patients diagnosed with T1G3 NMIBC that patients with a history of heavy and long-term smoking faced a more than twofold increased risk of disease progression compared to nonsmoker patients (HR 2.35; 95% CI: 1.7-3.2; P < 0.01) and a significantly poorer PFS for patients with a history of heavy long-term smoke exposure (P < 0.01). Patients with heavy long-term smoking exposure according to the EAU21 high-risk group had a PFS comparable to very high-risk patients and high-risk patients with heavy long-term smoking exposure showed a higher risk of progression when compared to the high-risk group (HR 1.4; 95% CI: 1.3-1.6; P < 0.01). Conclusions: This study adds valuable information on the relationship between smoking and the progression of NMIBC and BCG therapy. The findings emphasize the need for healthcare providers to consider a patient's smoking history when managing NMIBC and express the need for individualized smoking cessation counseling and individualized treatment approach

A prospective survey in European Society of Cardiology member countries of atrial fibrillation management: baseline results of EURO bservational Research Programme Atrial Fibrillation (EORP-AF) Pilot General Registry

Aims: Given the advances in atrial fibrillation (AF) management and the availability of new European Society of Cardiology (ESC) guidelines, there is a need for the systematic collection of contemporary data regarding the management and treatment of AF in ESC member countries. Methods and results: We conducted a registry of consecutive in- and outpatients with AF presenting to cardiologists in nine participating ESC countries. All patients with an ECG-documented diagnosis of AF confirmed in the year prior to enrolment were eligible. We enroled a total of 3119 patients from February 2012 to March 2013, with full data on clinical subtype available for 3049 patients (40.4% female; mean age 68.8 years). Common comorbidities were hypertension, coronary disease, and heart failure. Lone AF was present in only 3.9% (122 patients). Asymptomatic AF was common, particularly among those with permanent AF. Amiodarone was the most common antiarrhythmic agent used (~20%), while beta-blockers and digoxin were the most used rate control drugs. Oral anticoagulants (OACs) were used in 80% overall, most often vitamin K antagonists (71.6%), with novel OACs being used in 8.4%. Other antithrombotics (mostly antiplatelet therapy, especially aspirin) were still used in one-third of the patients, and no antithrombotic treatment in only 4.8%. Oral anticoagulants were used in 56.4% of CHA 2DS2-VASc = 0, with 26.3% having no antithrombotic therapy. A high HAS-BLED score was not used to exclude OAC use, but there was a trend towards more aspirin use in the presence of a high HAS-BLED score. Conclusion: The EURObservational Research Programme Atrial Fibrillation (EORP-AF) Pilot Registry has provided systematic collection of contemporary data regarding the management and treatment of AF by cardiologists in ESC member countries. Oral anticoagulant use has increased, but novel OAC use was still low. Compliance with the treatment guidelines for patients with the lowest and higher stroke risk scores remains suboptimal. © The Author 2013